/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/CollectionPropertyFacade.h
Add new properties, and return the index of the first added property.
int32 AddProperties ( const [TArray](API\Runtime\Core\Containers\TArray)< [FString](API\Runtime\Core\Containers\FString) > & Keys, [ECollectionPropertyFlags](API\Runtime\Chaos\Chaos\Chaos__Softs__ECollectionPropert-) Flags )